The expression of metalloproteinases in the lumbar disc correlates strongly with Pfirrmann MRI grades in lumbar spinal fusion patients

Exploring the Causal Relationship Between the Plasma Levels of MMP1 (Matrix Metalloproteinase-1), MMP3, MMP7, MMP10, and MMP12 and Intervertebral Disc Degeneration: Mendelian Randomization

Background

Several matrix metalloproteinases (MMPs) have been reported to be associated with intervertebral disc degeneration (IDD) in several previous studies. However, the causal relationship between MMPs and IDD remains unclear. In this study, Mendelian randomization (MR) was used to analyze the causal relationship between the plasma levels of multiple MMPs and the risk of IDD.

Methods

The GWAS data of the plasma levels of MMP1, MMP3, MMP7, MMP10, and MMP12 were derived from the genome-wide variation associations of 21 758 European individuals. The genetic associations of the variants with IDD were investigated in the largest genome-wide association study from GWAS pipeline using Phesant derived variables from UKBiobank (1045 cases; 461 965 controls). We used a two-sample MR method to evaluate the causal relationship between these five MMPs and IDD. The causal effects were examined by inverse variance weighted (IVW) test. And sensitivity analysis was performed using Q test of IVW and MR-Egger, MR-Egger-intercept and MR-PRESSO.

Results

We found a significant correlation between increased the plasma level of MMP3 and an increased risk of IDD (IVW: OR 1.000564, 95% CI 1.0000304-1.00110; p = 0.0383). The heterogeneity test (MR-Egger Q test: p = 0.346 and IVW Q test: p = 0.460) indicated that there was no heterogeneity in this instrumental variable on the surface. Also, no directional horizontal pleiotropy was observed in the MR analysis (MR-Egger, p = 0.708 and MR-PRESSO, p = 0.609). There was no significant correlation between the plasma levels of MMP1, MMP7, MMP10, and MMP12 and an increased risk of IDD.

Conclusion

Our MR analysis found that there is a potential causal relationship between increased the plasma level of MMP3 and the risk of IDD in the European population. There is no potential causal relationship between the plasma levels of MMP1, MMP7, MMP10, and MMP12 and an increased risk of IDD.

In vitro and ex vivo screening of microRNA combinations with enhanced cell penetrating peptides to stimulate intervertebral disc regeneration

Background

Low back pain (LBP) is predominantly caused by degeneration of the intervertebral disc (IVD) and central nucleus pulposus (NP) region. Conservative treatments fail to restore disc function, motivating the exploration of nucleic acid therapies, such as the use of microRNAs (miRNAs). miRNAs have the potential to modulate expression of discogenic factors, while silencing the catabolic cascade associated with degeneration. To deliver these miRNAs, nonviral cell penetrating peptides (CPPs) are gaining favor given their low immunogenicity and strong targeting ability. Single miRNA therapies have been investigated for IVD repair, however dual miRNA delivery strategies have not been commonly examined and may augment regeneration.

Materials and methods

Transfection of four pro-discogenic miRNAs (miRNA mimics:140-5p; 149-5p and inhibitors: 141-3p; 221-3p) and dual delivery of six miRNA pairings was performed using two CPPs, RALA and GET peptide (FLR), in primary rat NP monolayer culture, and in an ex vivo organ culture model of rat caudal discs. Protein expression of discogenic (aggrecan, collagen type II, and SOX9) and catabolic markers (ADAMTS5 and MMP13) were assessed.

Results

Monolayer investigations signified enhanced discogenic marker expression following dual miRNA delivery, signifying a synergistic effect when compared to single miRNA transfection. Utilization of an appropriate model was emphasized in our ex vivo organ culture experiment, revealing the establishment of a regenerative microenvironment characterized by reduced catabolic enzyme activity and enhanced matrix deposition, particularly following concurrent delivery of FLR-miRNA-149-5p mimic and miRNA-221-3p inhibitor. Bioinformatics analysis of miRNA-149-5p mimic and miRNA-221-3p inhibitor identified distinct targets, pathways, and interactions, suggesting a mode of action for this amplified response.

Conclusion

Our findings suggest the potential of FLR-miRNA-149-5p + miRNA-221-3p inhibitor to create an anti-catabolic niche within the disc to foster regeneration in moderate cases of disc degeneration, which could be utilized in further studies with the overarching aim of developing treatments for LBP.

Expression of cytokines at baseline correlate/predict in the disc the outcome of surgery after disc degeneration: A 12-month follow-up study

BACKGROUND

Low back pain (LBP) is a highly prevalent condition that comprise a large portion of outpatient practice, challenging the diagnosis and treatment. However, the diagnostic tools are limited to clinical history, physical examination and imaging. Degenerative disc disease (DDD) is a significant cause of LBP, and emerging literature confirms the elevated levels of biomarkers in the discs. These biomarkers may serve as a tool for diagnosis, but may also be useful in predicting the treatment outcome. Here, we examine the expression of various cytokines on 1-year recovery from patients with LBP.

METHODS

Patient-reported outcome (PRO) in terms of pain intensity (VAS), disability (ODI), and quality of life (Eq-5D) is collected from 44 patients at baseline and 12 months after surgery to study the influence of baseline TNF-α, IL-1β, and IL-6 mRNA expression in both annulus fibrosus (AF) and nucleus pulposus (NP).

RESULTS

Between baseline and follow-up, our cohort showed improvement in VAS back pain (p < 0.001), VAS leg pain (p < 0.001), ODI (p = 0.02), and Eq-5D (p = 0.01). Baseline levels of IL-1 β was positively correlated with VAS back pain scores in AF (p = 0.05) and NP (p = 0.01) at 1-year follow-up. TNF-α expression at baseline was also positively correlated to ODI scores (p = 0.01) at follow-up and inversely correlated to improvements in ODI score between baseline and follow-up, suggesting that high TNF-α expression at baseline is associated with poor outcomes from surgery.

CONCLUSION

The results from our study support that TNF-α expression at baseline can serve as a very important predictor of treatment response from lumbar fusion surgery.

Title Changes in Plasma Levels of Selected Matrix Metalloproteinases (MMPs) Enzymes in Patients with Osgood-Schlatter Disease (OSD)

Background: Osgood-Schlatter disease (OSD) belongs to the group of sterile bone necrosis and mainly affects athletically active children. The pathogenesis of OSD is currently not fully understood, so the purpose of this study was to evaluate the concentrations of selected matrix metalloproteinases (MMPs)-MMP-2, MMP-3, MMP-7, MMP-9, MMP-10 and MMP-26 in patients diagnosed with OSD compared to patients with diseases other than sterile bone necrosis Methods: The study group included 140 patients with OSD, while the control group contained 100 patients with knee pain unrelated to sterile bone necrosis. The MMPs tested were determined by an enzyme-linked immunosorbent assay in plasma. Results: Patients with OSD had higher concentrations of MMP-2 and MMP-9 compared to the control group. The concentrations of MMP-7, MMP-10 and MMP-26 were lower in affected children. High values of diagnostic parameters-diagnostic accuracy (AC), sensitivity (SE), specificity (SP) and area under curve (AUC)-were obtained for MMP-7, MMP-9 and MMP-26. Conclusions: The collected results convince that MMP-7, MMP-9 and MMP-26 can be consider as a differential ancillary test between OSD and other knee pain and may be involved in the pathogenesis of this condition.

Importance of Metalloproteinase Enzyme Group in Selected Skeletal System Diseases

Bone tissue is a dynamic structure that is involved in maintaining the homeostasis of the body due to its multidirectional functions, such as its protective, endocrine, or immunological role. Specialized cells and the extracellular matrix (ECM) are responsible for the remodeling of specific bone structures, which alters the biomechanical properties of the tissue. Imbalances in bone-forming elements lead to the formation and progression of bone diseases. The most important family of enzymes responsible for bone ECM remodeling are matrix metalloproteinases (MMPs)-enzymes physiologically present in the body's tissues and cells. The activity of MMPs is maintained in a state of balance; disruption of their activity is associated with the progression of many groups of diseases, including those of the skeletal system. This review summarizes the current understanding of the role of MMPs in bone physiology and the pathophysiology of bone tissue and describes their role in specific skeletal disorders. Additionally, this work collects data on the potential of MMPs as bio-markers for specific skeletal diseases.

TMT-Based Proteomics Analysis of Senescent Nucleus Pulposus from Patients with Intervertebral Disc Degeneration

Lower back pain, a leading cause of disability worldwide, is associated with intervertebral disc degeneration (IDD) in approximately 40% of cases. Although nucleus pulposus (NP) cell senescence is a major contributor to IDD, the underlying mechanisms remain unclear. We collected NP samples from IDD patients who had undergone spinal surgery. Healthy and senescent NP tissues (n = 3) were screened using the Pfirrmann grading system combined with immunohistochemistry, as well as hematoxylin and eosin, Safranin O, Alcian blue, and Masson staining. Differentially expressed proteins (DEPs) were identified using quantitative TMT-based proteomics technology. Bioinformatics analyses included gene ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and protein-protein interaction (PPI) analyses. In addition, immunofluorescence was used to verify protein expression. In total, 301 DEPs were identified in senescent NP tissues, including 92 upregulated and 209 downregulated proteins. In GO, DEPs were primarily associated with NF-kappaB transcription factor, extracellular regions, cellular protein metabolic processes, and post-translational protein modification. The enriched KEGG pathways included TGF-β, Wnt, RAP1, interleukin-17, extracellular matrix-receptor adhesion, and PI3K/Akt signaling pathways. PPI analysis demonstrated interactions between multiple proteins. Finally, immunofluorescence verified the expressions of MMP3, LUM, TIMP1, and CDC42 in senescent NP cells. Our study provides valuable insights into the mechanisms underlying senescent NP tissues in IDD patients. DEPs provide a basis for further investigation of the effects of senescent factors on IDD.

Intervertebral disc degeneration-Current therapeutic options and challenges

Degeneration of the intervertebral disc (IVD) is a normal part of aging. Due to the spine's declining function and the development of pain, it may affect one's physical health, mental health, and socioeconomic status. Most of the intervertebral disc degeneration (IVDD) therapies today focus on the symptoms of low back pain rather than the underlying etiology or mechanical function of the disc. The deteriorated disc is typically not restored by conservative or surgical therapies that largely focus on correcting symptoms and structural abnormalities. To enhance the clinical outcome and the quality of life of a patient, several therapeutic modalities have been created. In this review, we discuss genetic and environmental causes of IVDD and describe promising modern endogenous and exogenous therapeutic approaches including their applicability and relevance to the degeneration process.

Metalloproteases in Pain Generation and Persistence: A Possible Target?

Matrix metalloproteinases (MMPs) are a large family of zinc-dependent proteolytic enzymes associated with extracellular matrix protein turnover and tissue degradation. They participate to many different physiological reactions but are also hyperactivated in several diseases. Various literature studies have documented that MMPs play a role in the modulation of neuropathic and nociceptive pain. The heterogeneity of clinical and pre-clinical data is an important issue in this experimental context. Despite the presence of a good number of studies on MMP inhibitors, these drugs showed scarce efficacy and relevant side effects. In the present manuscript, we reviewed studies in the literature that define a possible role of MMPs in pain and the effects of their modulation.

Microfluidic Electroceuticals Platform for Therapeutic Strategies of Intervertebral Disc Degeneration: Effects of Electrical Stimulation on Human Nucleus Pulposus Cells under Inflammatory Conditions

The degeneration of an intervertebral disc (IVD) is a major cause of lower back pain. IVD degeneration is characterized by the abnormal expression of inflammatory cytokines and matrix degradation enzymes secreted by IVD cells. In addition, macrophage-mediated inflammation is strongly associated with IVD degeneration. However, the precise pathomechanisms of macrophage-mediated inflammation in IVD are still unknown. In this study, we developed a microfluidic platform integrated with an electrical stimulation (ES) array to investigate macrophage-mediated inflammation in human nucleus pulposus (NP). This platform provides multiple cocultures of different cell types with ES. We observed macrophage-mediated inflammation and considerable migration properties via upregulated expression of interleukin (IL)-6 (p < 0.001), IL-8 (p < 0.05), matrix metalloproteinase (MMP)-1 (p < 0.05), and MMP-3 (p < 0.05) in human NP cells cocultured with macrophages. We also confirmed the inhibitory effects of ES at 10 μA due to the production of IL-6 (p < 0.05) and IL-8 (p < 0.01) under these conditions. Our findings indicate that ES positively affects degenerative inflammation in diverse diseases. Accordingly, the microfluidic electroceutical platform can serve as a degenerative IVD inflammation in vitro model and provide a therapeutic strategy for electroceuticals.